High-capacity aerobic wastewater treatment systems for treating relatively large volumes of organic waste.
Many wastewater treatment systems use colonies of cultivated strains of microorganisms to decompose organic wastes. For instance, in U.S. Pat. Nos. 4,670,149 (Francis) and 4,680,111 (Ueda), bacterial incubators are floated or suspended near, or just below, the surface of the water being treated. Because the colonies used to treat wastewater require oxygen, it is necessary to aerate or oxygenate the wastewater being treated to sustain the colonies. Moreover, because many industrial sites have large bodies of wastewater (e.g., ponds, lagoons, etc.), there is a need for economical aeration systems that can effectively oxygenate large volumes of wastewater.
Conventional aeration systems can include a wide variety of devices designed to increase dissolved oxygen content in water. Wastewater treatment engineers have discovered that aeration devices that produce very fine bubbles are particularly well-suited for oxygenating wastewater. Examples of such devices are disclosed in U.S. Pat. Nos. 3,490,752 (Danjes et al.), 3,664,647 (Snow), and 4,215,082 (Danel). Other well-known aeration devices designed for use in larger bodies of water aerate wastewater by agitation. These devices use paddle-wheels, pumps, and water jets. For example, U.S. Pat. No. 4,072,612 (Daniel) discloses a large mixing pump, while U.S. Pat. No. 3,984,323 (Evens) and French Patent No. 1,377,571 disclose water-jet mixers.
Although these systems can effectively oxygenate relatively small volumes of wastewater, because several conventional processing units may be needed to facilitate the treatment of large volumes of waste, it is often too costly for industries to use conventional systems to oxygenate large volumes of wastewater. In addition, since multiple conventional processing units are often used to treat large volumes of wastewater, transportation can be cumbersome and expensive. Large volumes of wastewater are particularly common at food processing plants, pulp and paper facilities, chemical and textile companies, and municipal wastewater treatment plants. Because of the expense associated with oxygenating large volumes of water using multiple conventional aeration systems, there is a need for more economical, high-capacity aeration systems.
We have developed an improved, lower cost, high-capacity wastewater aeration system to stimulate enhanced bio-activity for the treatment of relatively large volumes of wastewater. Our system includes three main components: a large main processing float, a plurality of smaller xe2x80x9cbio-blockxe2x80x9d processing floats, and an air delivery system to deliver oxygen to the wastewater being treated. The air delivery system delivers oxygen to the wastewater beneath the large main processing float and beneath each smaller bio-block float so that biological media submerged beneath the floats are sustained.
By positioning a plurality of smaller bio-block floats in proximity to the large main processing float, we can treat a significantly larger volume of wastewater than we could using a single, large main processing float. Moreover, by using a plurality of smaller bio-block floats instead of multiple large processing floats to increase the system""s aerobic treatment capacity, we can increase treatment capacity and enhance bio-activity more cost-effectively. In addition, the smaller bio-block floats also make transportation of the system less cumbersome and less costly. Our improved wastewater aeration system offers increased treatment capacity and high mobility and provides facilities that generate relatively large volumes of organic waste as an economic alternative to more costly conventional aeration systems.